<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>CSS3 transform-origin</title>
</head>
<style>
*{
    margin: 0;
    padding: 0;
}
.container{
    width: 100px;
    height: 100px;
    margin: 100px auto;
    background-color: #0033dd;
}
.element{
    width: 100px;
    height: 100px;
    opacity: 0.8;
    background-color: #CC9966;
    transition: transform 3s;
}
.container:hover .element{
    opacity: 1;
    transform: rotate(360deg);
     /* 参数 x轴 y轴 坐标 */
    /* transform-origin: center middle; */
    transform-origin: 0 0;
}
</style>
<body>
    <div class="container">
        <div class="element"></div>
    </div>
</body>
</html>